Endpoints for clinical trials and revised assessment in neuro-oncology

Purpose of review Recent advances in survival for patients with newly diagnosed and recurrent brain tumors, combined with the development of an ever-increasing number of potential treatments, has led to significant growth in the number of clinical trials for patients with brain tumors. Suitable clinical trial design and endpoints are vital for successfully evaluating these new treatments that may continue to improve outcome. However, inadequacies of clinical trial endpoints have challenged how best to evaluate promising new therapeutics. Recent findings Pseudoprogression and pseudoresponse confound imaging-based endpoints, including overall radiographic response and progression-free survival. Overall survival is still regarded as the definitive endpoint, but recently identified active salvage agents such as bevacizumab may diminish the association between presalvage therapy and overall survival, making interpretation of clinical trial results difficult. Novel imaging and the assessment of patient function, quality of life (QOL), and cognition are more frequently employed as endpoints. Summary An awareness of the benefits and imperfections of clinical trial endpoints will lead to improved clinical trial design and results. Validated endpoints of patient function, QOL, and cognition are available and increasingly valued as secondary endpoints.